Refrigeration apparatus



v. v. TORBENSEN 2,340,780

REFRIGERATION APPARATUS Filed May 26, 1941 3 Sheets-Sheet 1 H L Wm QINVENTOR V/GGOKTORBENSEN BY W1C.

ATTORNEYS Feb. 1, 1944.

Feb, 1, 1944. v, v. TQRBENSEN 2,340,780

REFRIGERATION APPARATUS Filed May 26, 1941 s Shets-Sheet 2 m4 j 5/ a 39V F I Y I 1 -"50 i I II J [B 1 -11 m] RIG 7 INVENTOR V/GGO M TORBENSENBY flmv iwn ATTORNEYS Feb. 1, 1944. v. v. TORBENSEN REFRIGERATIONAPPARATUS Filed May 26 1941 3 Sheets-Sheet 3 F/Ql/ INVENTOR V1060VERBEMSEN.

. ATTORNEY Patented Feb. 1, 1944 Application May 26, 1941, Serial No.395,163

7 Claims.

The present invention pertains to improvements in refrigerationapparatus and methods of construction.

An object of the invention is to provide improved means for maintaining'two temperature zones in a single refrigerator.

Another object is to provide improved apparatus of the above typeembodying a mild temperature non-freezing compartment for ordinary foodstorage and a low temperature or deep-freezing compartment for storageof frosted foods, ice cubes and the like.

A further object is to provide a structure of the above type in whichthe temperature and humidity of each compartment are unaffected by thoseof the other.

Another object is to provide easy access to each compartment withoutaffecting the other.

Another purpose is to provide an improved deep-freezing structure.

A further object is to provide a simplified deep freezing unit includinga two-passage refrigerating tube coiled about and intimately joined tothe walls of an inner receptacle.

Another object is to provide a unit adapted by counterflow ofrefrigerant through the two tubing passages to maintain an eventemperature throughout the inner freezing surface.

Another object is to provide suitable methods for forming thetwin-passage tube and for constructing the low temperature freezerembodying the same.

Another object is to provide an improved nonfreezing cooling coil forthe mild temperature compartment.

A further object is to provide improved means in conjunction with thenon-freezing coil for augmenting the humidity in the mild temperaturezone.

A still further object is to provide a unitary structure including theabove two different temperature devices and adapted to be readilyinstalled as a unit in the body of the refrigerator.

Other objects and advantages of the invention will appear during thecourse of the following description, in connection with the accompanyingdrawings, in which- Figure 1 is a vertical sectional view of arefrigerator embodying the invention, the section being taken in theplane l-l, Figure' 2;

Figure 2 is a similar view taken in the 2-2, Figure 1;

Figure 3 is an enlarged detail cross section of the twin-passage tubing,illustrating a method of forming the latter;

plane sulated front door 22.

Figure 4 is an enlarged top view of the deepfreezing unit withsurrounding material removed to illustrate the structure;

Figure 5 is a front view of the same partiallyin section on the lines5-5, Figure 4;

Figure 6 is a detail sectional view of the closed end of the twinpassage tube in the plane 6-6, Figure 7, showing a method of connectingthe two passages;

Figure 7 is another sectional view of the same in the plane 1--'|,Figure 6;

Figure 8 is a detail section in'the plane 88, Figure 9, illustrating ameans of affecting outside connections to the twin passages;

Figure 9 is another sectional view of the same in the plane 99, Figure8;

Figure 10 is an enlarged front view of the nonfrosting cooling apparatushalf in section;

Figure 11 is a plan view of the humidifying pan or grid;

Figure 12 is a plan view of the drain pan or id;

Figure 13 is a rear elevation showing an alternative form of thedeep-freezing unit;

Figure 14 is a detail longitudinal section in the plane "-14, Figure 15,showing one type of end fitting for a common exterior connectionto bothof the twin tube passages;

Figure 15 is a cross sectional view of the same in the plane |5'-l5,Figure 14;

Figure 16 is a fragmental detail elevation illustrating another methodof providing for a common end connection to both of the twin passa es:

Figure 17 is an end sectional view in the plane l'l-ll, Figure 16, and

Figure 18 is a fragmental sectional view showing a detachablestandpipeapplied to the drain grid.

Referring to Figures 1 and 2, the numeral 20 generally denotes arefrigerator cabinet having an outer shell 2| and equipped with an in-An inner shell. 23 xtends to a point above the door 22 to define a lowerstorage chamber 24, suitable heat insulating material 25 being providedbetween-the bottom, sides and back of inner shell 23- and the outershell or casing 2|.

A pan 26, closely fitting in the upper portion of the outer casing 2|,engages the top of the inner shell 23. A low-temperature cooler ordeep-freezer 21, illustrated as of rectangular shape and described indetail hereinafter, is disposed in the pan 26. A layer 28 of insulatingmaterial of substantial thickness is provided between the cooler 21 andthe bottom of the pan 26,

and heavy insulation 28 also surrounds .the vertical walls of thefreezer. A top plate 30, preferably secured to the open upper rim-of thefreezer 21, engages the top of the refrigerator shell 2|.

An insulated lid 3| is attached by means of hinges 32 to the rear wallof the outer shell 2|, this lid forming the top of the refrigeratorstructure and normally serving as a main insulating closure for thecompartment 33 of the deepfreezing unit 21.. One or more suitablesealing gaskets 34 may be provided between the lid 3| and the top plate30, and the lower side and front edges of the lid may terminate in abead 35 overlapping the upper edges of the outer casing 2|.

A non-frosting non-dehydrating cooler 31, hereinafter also described indetail, is suspended by means of strap brackets 31* from the bottom 36of the pan 28,

It will be seen that the pan 26, its contained deep-freezer 21 and itsdepending lower cooler 31 comprise a unitary structure adapted to bebodily lowered into the main refrigerator casing 2|, the bottom of pan26 becoming the top liner of the mild temperature chamber 24 and properly positioning the cooler 31 therein, while the insulating layer 28 inthe pan provides a bar against heat leakage from chamber 24 to thedeep-freezer compartment 33.

The deep-freezer 21 in preferred form is constructed as follows,referring first to Figures 4 and the inner lining walls 38 and bottom 39of the compartment 33 are made of sheet metal.

A coil of tubing 40 is closely wound around the walls 38 and intimatelyjoined thereto throughout, preferably by the well-known process termedstitch-welding, in which two flat surfaces are electro-welded togetherin a continuous band by means of a heavy current directed through themfrom suitable electrodes engaging the adjacent outer surfaces.

The tubing 48 is preferably of the shape illustrated, shown in enlargedcross section in Figure 3, which figure also illustrates a method offorming the tubing. In this method, a round or other conveniently shapedtube of suitable metal such as soft drawn steel. copper, or the like,isfed between two specially shaped rolls II and 42. The roll 42 flattensone side 43 of the tube to a substantial width while the double concaveroller 4| depresses the middle of the opposite wall to form a centralsubstantially fiat portion 44 which is pressed against the opposite fiatwall 43; at the same time the contours of the rolls form tubular sideportions 45 and 45 defining twin passages 46 and 41. The central fiatportion 44 is then hermetically fused or welded to the wall 43 by thestitch-welding method mentioned above. The tubing may also be hot-rolledto the described shape, the welding then taking place during therolling, after the manner of producing the welded seams in lap-weldedsteel pipe. The twin-passage tubing 40, formed as de Y scribed andhaving been annealed if necessary,

- on the size of unit.

rent and for sound and even welding; it will be obvious to those skilledin the art that this result would not be feasibly the case with ordinarytubing lacking the above provision.

Applicant is aware that cooling units are made by welding or otherwisejoining together two sheet members, in one or both of, which channelshave previously been pressed to form passageways between the memberswhen joined. However, the application of this method with reasonableeconomy is limited to high production of a comparatively small number ofshapes and models, due to the necessity of providing expensive dies foreach model; the necessity for special dies also places a practical upperlimit With applicants method, on the other hand, intimately weldedcooling units may be cheaply produced in any desired quantities, largeor small, and with no limitation as to size, special large dies notbeing required.

Furthermore, it is possible with the present invention to form thecooling coils with the adjacentwalls of successive turns abutting as inFigure 5, allowing a maximum length of passage thus forming a U-junctionor opening 49 between the passages.

The lower ends of both passages 46 and 41 are pinched and welded shut asshown in Figure 8. Inlet and outlet fittings 50 and 5| are secured insealing relation to the back of the tubing 40 by welding, brazing or thelike. The outlet fitting 5| has an internal .opening' through a hole 53from the passage 41 as shown in Figure 9, while the inlet fitting 50 isprovided with a similar opening 52 into the passage 46. A pipe 54, se-

cured in or formed on the fitting 50, is adapted to be attached to anexpansion valve 55, Figures 1 and 2. Similarly, a pipe 56 from thefitting 5| is provided for a suction connection.

In operation, when refrigerant is admitted through pipe 54 from theexpansionvalve, it travels the entire length of the tubing 48 in thepassage 46, through the U-connection 49, (Figure 6), thence back throughthe second passage 41 to the suction pipe 56. The structure thus causesevaporation in direct counterfiow relation between all adjacent passagesthroughout. the entire coil. The eifect of this complete counterfiowevaporation is to equalize or counterbalance any tendency toward anevaporating temperature gradient due to friction in the passages and togravity, producing a substantially constant uniform temperaturethroughout the unit and thereby avoiding comparatively warm or coldzones such as occur in prior structures, for example in the usual typeof ice-cream cabinets.

A further advantage of the described structure is that it locates theinlet and suction near together at one end of the coil, promotingsimplicity, compactness, and requiring a minimum of exterior connectingtubing.

After the deep freezer has been constructed as described, it may begiven a coating of corrosion-reslsting metal by hot-dipping or othersuitable process; or if desired when metal of sufficiently high meltingpoint has been used in construction, the interior of the freezer may begiven a vitreous lining.

A removable partition 51 is provided in the deep-freezer 21, employedfor-example in case one portion of the interior is to be used forstoring ice cubes and the other for frozen foods. Sub-lids 58 and 59having hinges 60 removably clipped to the partition 61, are adapted toprotect each of the two sub-compartments of compartment 33 from heatentry while the other is open. The partition 51 and sub-lids 58 and 59may be made of metal or of a suitable plastic sheet having low-heatconductivity.

Referring to Figures 1, 2 and 10, the mild temperature cooler 31comprises a'coil of finned tubing 6| secured at the sides to the strapsor brackets 31 by means of U-bolts 62. Small saddles 63, preferably ofheat insulating material, are provided between the straps and the tubingto prevent crushing the fins 64, as shown in Figure 10.

The coil 6| is provided at its rear upper left comer with an expansionvalve 65 of any suitable type, herein illustrated as of the thermostatictype having the usual 'feeler bulb 66 attached to the suction tube 61 ofcoil 6|, Figure 10. The suction line from coil 6| and the liquid tube 68to the expansion valve 65 are led outward through a slot 69 in the rearwall of the refrigerator cabinet 29, a suitable union being provided inthe suction line to facilitate installation as hereinafter set'forth.

The inlet pipe 54 and suction pipe 56 of the hind. the rear upper rightcomer of the cooler 31 as shown in Figures 1 and 2. The liquid line 1|of the valve 55 and the suction line 12 connecting to the pipe 56 areled out through the slot 69, the suction connection also being madethrough a union 13. The valve 55 may also be of the thermostatic typewith the usual feeler bulb 55 clamped in thermal contact with thesuction line 12. A detachable insulating shield may be provided aboutthe low temperature expansion valve and suction connections as shown inFigure 2, to prevent any air dehydration due to frosting of thesemembers.

other so that when in place they press firmly against the'strap ends 16,thereby preventing looseness and possible rattling.

The sides 19 have suitable openings or windows 83 (Figures 3 and 10), toallow and promote circulation of air through the cooler 31.

A humidifying receptacle 84 for water, preferably of grid form as shownin Figures 1, 2, l0 and 11, is slidably mounted on angles 85 secured tothe inner sides of straps 31 above the coil 6|, and is removable througha slot 86 in the front plate 88. The humidifier grid comprises shallowlongitudinal channels 81 connected at the ends by cross channels 88.Open slots 89 between the channels 81 are provided to allow free aircirculation over the channels and downward through the grid. Thechannels have substantially vertical sides in order to providepractically constant evaporating surface area with varying depths ofwater therein.

' A lip 90 on the front of the grid receptacle 84 serves as a handle forremoving the grid through the slot 86 and also facilitates refilling thereceptacle with water.

Bolted to the inturned lower ends of the straps 31 is a drain grid 9|,shown in plan view in Figure 12, and comprising narrow longitudinalchannels 92 connected by a narrow cross channel 93 at the front, and bya wide basin 94at the rear. The longitudinal channels 92 and frontchannel 93 underlie the longitudinal and front tubing portions of thecoil 6|, being made with r I only sufflcient width to catch any dripfrom. the

The straps 31 are secured to the pan bottom I 36 by cap screws 14passing through the outwardly turned upper ends 15 of the straps andscrewed into blind spuds 16 permanently sealed to the pan bottom 36. Thestrap ends 15 are spaced away from the pan 36 by washers 11. A U-shapedone pieoe shield 18 comprising side plates 19 and a front plate 88,encloses the complete assembly of the cooler 31 and related parts.

The upper edges 8| of the sides 19 are turned inward to overlie the tipsof the strap-ends 15 as shown in Figure 10, the ends 15 thus providing ameans of retaining the shield 18 in place. Notches 82, Figure 2, in theedges 8| allow the shield 18 to be installed by raising it upward justinside the front wall of the refrigerator until the edges 8| pass thestrap ends 15. then pushing the entire shield back into position asshown. Y

Obviously the shield may be removed by the reverse procedure withoutdisturbing any of the other apparatus. The shield 18 is preferablyformed with the sides 19 bent slightly toward each ,finned tubing andinsuring free air passage through the large longitudinal openings 95.The rear basin 94 underlies the rear tubing portion of the coil 6| andalso extends rearwardly, as shown in Figure 2, to catch any possibledrip from the expansion valves 55 and and the suction connections.

The bottom of the grid 9| slopes downward throughout toward a drain hole96 provided with a small downwardly extending spout 91 (Figure 2). Thechannels are preferably V- shaped in order to minimize the possibilityof any splashing. The screw connections to the straps 31 are madethrough bosses98 extending upward from the bottom of the grid. and

the outer rim 99 of the grid is flared outward adjacent the bosses tocatch any drip from the straps.

Both the humidifying receptacle orgrid 84 and the'drain grid 9| may. bemade of stamped or die cast metal, or if desired may be made of suitablewaterproof plastic material.

To catch the drip from the spout 91, a jar I09 or other suitablereceptacle may be placed under the spout on a convenient shelf IN, orthe jar maybe placed on the bottom of the compartment 24 with some typesof shelf arrangements. Obviously,the compartment 24 may be equipped withany desired number and arrangement of shelves, only the shelf |0| beingshown herein for purposes of illustration.

In assembling the refrigerator. the entire refrigerating structure,comprising the pan 26, the insulated deep-freezer 21 contained in thepan. the mild temperature cooler 31, and the expansion valves 55 and 65,may be Dre-assembled as a unit. The lid 3| having been opened, theunitary. sub-assembly may be lowered bodily into the casing from thetop, after which the connections to the liquid and suction lines 68, 1|,61 and 12, are made behind the cooler 31. as shown. ,Removal of theshield 18, as previously described, allows access to the various unionconnections from either side.

The slot 69 may be made sufliciently large to allow insertion of theliquid and suction line tubes with their respective union fittingsalready applied to them, these tubes preferably being placed in positionbefore installation of the above described unitary sub-assembly. Afterinstallation, the slot 89 is suitably sealed against leakage of air andheat.

It will be understood that the suction and liquid lines 61, I2, 68 and Hare exteriorly connected to any suitable type of refrigerating machineequipped with controls for operating the deep-freezer 21 and the cooler31 at their different. proper temperatures, but as such machines andcontrols are well known in the art and form in themselves no part of thepresent invention. they are not shown herein.

The refrigerator 2!! may be provided with the usual bottom compartmentI02 for the refrigerating machine, this compartment being made ofminimum height to minimize the overall height of the cabinet/and alloweasy access to the deep-freezer compartment 33.

The top plate 30. (Figures 1 and 2), is preferably secured in sealingrelation to the upper edge of the pan 26, thus insuring completeprotection for the insulation 28 and 29 at all times against entry ofmoisture. -Similarly, the insulating material 25 in the lower portion ofthe cabinet is sealed by a thin plate I03 secured to the outer shell 2|and inner shell 23 at the upper end of the latter.

In operation, the deep-freezer 2'! is normally operated to maintain thecompartment 33 at a low temperature suitable for proper storage offrosted foods, ,pre-frozen ice cubes and the like; while the lower coil6| maintains the compartment 24 at a mild temperature proper forordinary food storage. Access to the deepfreezer compartment 33 is ofcourse obtained by raising the lid 3|, an advantageous arrangement initself since there is less tendency for escape of cold air upward duringopening than in the case of sharp freezers opening horizontally.

The front door 22 provides access to the compartment 24 in the usualmanner. The heavy insulation 28 in the pan 28 prevents the temperatureof the two compartments from affecting each other as noted.

A drain I84 (Figures 4 and leads from the bottom of compartment 33through. the pan bottom 36. The tube I05 Of drain i4 is preferably madeof suitable plastic pipe such as Bakelite, having low heat conductivity,and is normally closed at the bottom by an insulating stopper or tacleplaced on a shelf in compartment 24 below the drain tube. The drainingof compartment 33 may be carried out during full normal refrigeratingoperation of the lower compartment 26, since the drip of cold water fromthe tube 1 05 can have no appreciable influence on the temperature orhumidity'in the lower compartment. Similarly,

refrigeration of the lower compartment 24 may be discontinued forwashing out or any other purpose without affecting the operation of thedeepfreezer 21. c

The tubing GI and fins 64 0f the cooler 36 have an area sufilciently,great to allow proper cooling without coil temperatures low enough tocause frosting and consequent serious dehydration. Such water ofcondensation as occurs on the coil is partially restored to the airstream from the wetted surfaces and the drip downward through the coil,the excess being caught by the drain grid 9|. Meanwhile evaporation fromthe previously supplied water surface in the upper humidifying grid 84augments the moisture supply of the air in the compartment. The form ofthe grid 84 and its location as shown, where its large water surface isswept by the warmest air in the compartment moving inward and downwardtoward the coil 6|, causes the grid to operate with maximumeffectiveness to maintain a properly high balance of humidity, at thesame time maintaining simplicity and making unnecessary the use ofcumbersome and often ineffective devices such as forced humidifiersincluding fans and the like.

The grid forms Of both the receptacle 84 and the drain member 9| permitthese devices to perform their functions with minimum interference withair circulation, in contrast to the serious interference caused by thelarge solid drip pans used in ordinary practice.

From the foregoing description, it will be evident that while therefrigerating apparatus for both temperatures comprises a unitarysub-assembly readily installed in orremovable bodily from the maincabinet shell 2|, the structure provides for completely independentoperation of the two zones, neither being affected by the normaloperation, opening and closing, or even discontinuance of operation ofthe other. these qualities make possible more convenient and economicaloperation than can be achieved by prior structures wherein bothtemperature zones are located in a single compartment or served by asingle main door, often with little or no effective insulation betweenthe zones; and with consequent requirement for frequent defrostings;furthermore, as previously noted, the unitary refrigerating structuredescribed provides for economical manufacture and easy assembly.

It will be observed that the deep freezer com-' partment 33 is of largecapacity and easily accessible throughout. This large compartment isespecially adapted for keeping frozen foods and economical storage ofpre-frozen ice cubes, but it is obvious that it may also be employed forfreezing ice cubes by simply placing the necessary trays of watertherein.

While the counterflow arrangement of the twin-tubing 40 as described ispreferred, for some purposes it maybe desired to employ the generalmethod set forth to construct coolers in which circulation ofrefrigerant takes place in parallel through the twin passages 46 and 41,such a cooler being shown in Figure 13. For this purpose, endfittingsIII! of the type shown in detail in Figures 14 and 15 maybe welded,brazed or otherwise secured to the ends of the tubing. Referring,

to Figure 14, the fitting I 01 has a single exterior connecting openingI08 and a common exterior passage I09 opening into both passages 48 and41.

Another method of providing for a common connection to both passages isillustrated in Fig- ,Qures' 16 and 17, wherein the rolled and welded.zone 44 is terminated, as previously noted, at any desired distancefrom the end of the tubing stock, thus leaving the unrolled portion H0round to Obviously permit attachment of the usual flared tubing unionsor the like. The fittings I01, 50 and BI are illustrative, as obviouslya variety of types and forms of fittings such as Ts, U-bends, etc., maysimilarly be provided for any desired exterior connections to thetwin-passage tubing.

Referring again to themeans described for maintaining proper humidity inthe lower nonfreezing compartment 24, it will be obvious that in thecase of large refrigerators two or more humidifying grids 84 may be usedif-desired. It may also be desired in some cases to provide ahumidifying surfacebelow as well as above the non-frosting coil 6|. Aconvenient means of maintaining this surface is illustrated in Figure18. A small stand-pipe H2, illustrated as made of rubber, is detachablyinserted in the drain hole 98 of the lower grid 9|, the upper end of thepipe being a short distance below the top level of the rim 9|.

Water dripping from the coil 6| accumulates in the grid 9| until itslevel H3 reaches the top of the standpipe H2, after which any excessoverflows through the pipe and out through the spout 91. The grid may beinitially filled with water to the top of the standpipe, the levelthereafter being maintained by drip from the coilas set forth.

While the throughout in preferred form, it is not limited to the precisestructures and procedures set forth, as various modifications may bemade without departing from the scope of pended claims.

What is claimed is: 1. In a refrigerator structure, in combination, acasing, an inner shell disposed in said casing the anand defining alower chamber therein, an insulating wall between said casing and theside and rear walls and bottom of said shell, a pan disposed in saidcasing above said shell, the bottom of said pan comprising the topclosure of said lower chamber, an evaporator structure attached to thebottom of said pan and depending there from in said lower chamber,-saidevaporator being adapted to provide amild temperature in said lowerchamber, a second evaporator structure in said pan and including anupwardly opening sharp freezing chamber, a body of insulating materialof substantial thickness forming an effective heat bar between the innersurfaces of said pan and the sides and bottom of said freezing inventionhas been described chamber, an insulated lid on said casing, saidlidnormally comprising a top closure for said sharp freezing chamber, and afront door on said cas me, said door normally comprising the frontclosure for said-lower chamber.

second evaporator structures comprise a unitary structure removableupward bodily from said casing.

3. A structure as claimed in claim 1 including means forming a drainfrom said freezing chamber into said lower chamber, and means operablein said lower chamber to close and open said drain.

4. A structure as claimed in claim 1 including regulating meansconnected to said first evaporatorstructure and adapted to regulateoperation thereof above the freezing point of water, and regulatingmeans connected to said second evaporator structure and adapted toregulate operation thereof below thefreezing point of water, both saidregulating means being comprised in said lower chamber. I

5. In a refrigerator structure, in combination, a cabinet including alower chamber, means including an evaporator and forming a sharpfreezing chamber in the upper portion of said cabinet, a secondevaporator in said lower chamber and adapted to maintain a mildtemperature therein, means in said lower chamber to independentlyregulate said respective evaporators to produce 'a sharp freezingtemperature in said upper chamber and said mild temperature in saidlower chamber, and means forming a common insulating wall between saidchambers to substantially prevent inter-dependence of said temperatures,

said two evaporators and said wall comprising a unitary structureremovablebodily from said cabinet.

6. In a refrigerator structure, in combination,

a cabinet, a sharp freezer in the upper portion of said cabinet, a lidon the top of said cabinet and normally forming a closure for said sharpfreezer, a mild temperature cooler in said cabinet below said sharpfreezer, means to individually control the temperatures of said sharpfreezer and said mild temperature cooler, walls of insu lation in thetop, the four sides and the bottom of said cabinet, saidinsulation beingthicker' about the top and the side walls of said sharp freezer than thethickness of the walls about said mild temperature cooler, and commoninsulating means between said sharp freezer and said mild temperaturecooler to prevent interdependence of said temperatures.

7. The structureaccording to claim 6,. including -VIGGO V. TORBENSEN.

